Circadian rhythm of cyclic nucleotide and GABA levels in the rat brain.


Daily variation in the levels of cyclic nucleotides and GABA was examined in seven brain regions of male Sprague-Dawley rats. Significant daily rhythm of cyclic AMP levels was found in the cerebellum and pons medulla oblongata. Circadian variation of cyclic GMP levels was found in the cerebellum, cerebral cortex, striatum, and hypothalamus. Daily variation… (More)